CENG 450 Computer Systems & Architecture Lecture 1

1. CENG 450Computer Systems & ArchitectureLecture 1 Amirali Baniasadi amirali@ece.uvic.ca

2. CENG 450: Computer Architecture Instructor: Amirali Baniasadi EOW 441, Only by appt. Call or email with your schedule. Email: amirali@ece.uvic.ca Office Tel: 721-8613 Web Page for this class will be at http://www.ece.uvic.ca/~amirali/courses/ceng450.html Text: Computer Architecture A Quantitative Approach Filth edition, by Patterson and Hennessy Lecture notes will be posted on the course web page in advance.

3. CourseStructure • Lectures: • 1 week on Overview and Introduction (Chap 1) • 2 weeks on ISA Design (Chap 2) • 6 weeks on Proc. Design (Chap 3 ,4) • 4 weeks on Memory and I/O (Chap 5) • Reading assignments posted on the web for each week. • NO Homework: Problems will be posted on the web site so you can prepare for exams/quizzes. • Quizzes: 4 in class quizzes. Dates will be announced in advance. • Note that the above is approximate.

4. Course Philosophy • Book to be used as supplement for lectures (If a topic is not covered in the class, or a detail not presented in the class, that means I expect you to read on your own to learn those details) • One Project (25%) • Four Quizzes (25%)- Will be announced in advance. • Final Exam(50%) • IMPORTANT NOTE: Must get passing grade in all components to pass the course. Failing any of the three components will result in failing the course.

5. Project • Labs start at Week of Jan 23rd. • Processor design.

6. Topics • Computer Architecture? • History • Technology • Moore’s law & Virtuous circle • Language evolution • Components of a computer • Instruction set architecture (ISA)

7. How many “computers” do you have? • Three different computing markets: 1.Desktop Computing: low-end systems, high performance workstations. Price $500 to $5000 2.Servers: web servers. Should be available and reliable. Availability: be ready if components fail. Scalability: ability to grow 3.Embedded computers: Hidden computers, ex. cell phones, washing machine, palmtop, watch… Minimize memory and power. Often not programmable.

8. What is “Computer Architecture” Computer Architecture: Behind the doors! Computer Architecture = Instruction Set Architecture + Machine Organization + Hardware Instruction Set Architecture: Visible to Compiler. RISC vs. CISC. Machine Organization: Importance of Von Newman design.

9. ISA • 1950s: Hardwired Control, easy to implement, limited resources • 1960s: Microprogramming, more flexibility. • 1970s: CISC: • Compilers in infancy so ISA designed for programmers. • Expensive & small memory: Highly encoded, Multiple size instructions (e.g., x86 from 1-17 bytes), ISA approximates high level languages, • 1980s: RISC: • Better compiler, cheaper memory, “elemental instructions” • 2000s: More resources, post-RISC? CISC:”walk-across-the-room-without-stepping-on-the-dog” RISC:”walk-walk-walk-step over dog-walk-walk”

10. History 1. “Big Iron” Computers: Used vacuum tubes, electric relays and bulk magnetic storage devices. No microprocessors. No memory. Example: ENIAC (1945), IBM Mark 1 (1944)

11. History Von Newmann: Invented EDSAC (1949). First Stored Program Computer. Uses Memory. Importance: We are still using the same basic design.

12. Computer Components Memory Processor (CPU) Printer Screen Disk . . . Output Control keyboard Mouse Disk . . . Input

13. Computer Components • Datapath of a von Newman machine OP1 + OP2 ... Op1 Op2 General-purpose Registers ALU i/p registers Op1 Op2 Bus ALU ALU o/p register OP1 + OP2

14. Computer Components • Processor(CPU): • Active part of the motherboard • Performs calculations & activates devices • Gets instruction & data from memory • Components are connected via Buses • Bus: • Collection of parallel wires • Transmits data, instructions, or control signals • Motherboard • Physical chips for I/O connections, memory, & CPU

15. Computer Components • CPU consists of • Datapath (ALU+ Registers): • Performs arithmetic & logical operations • Control (CU): • Controls the data path, memory, & I/O devices • Sends signals that determine operations of datapath, memory, input & output

16. Technology Change • Technology changes rapidly • HW • Vacuum tubes: Electron emitting devices • Transistors: On-off switches controlled by electricity • Integrated Circuits( IC/ Chips): Combines thousands of transistors • Very Large-Scale Integration( VLSI): Combines millions of transistors • What next? • SW • Machine language: Zeros and ones • Assembly language: Mnemonics • High-Level Languages: English-like • Artificial Intelligence languages: Functions & logic predicates • Object-Oriented Programming: Objects & operations on objects

17. Moore’s Prediction

18. 1 0 0 , 0 0 0 6 4 M 1 6 M 1 0 , 0 0 0 4 M y t i c 1 M a p 1 0 0 0 a c t 2 5 6 K i b K 1 0 0 6 4 K 1 6 K 1 0 1 9 9 6 1 9 7 6 1 9 7 8 1 9 8 0 1 9 8 2 1 9 8 4 1 9 8 6 1 9 8 8 1 9 9 0 1 9 9 2 1 9 9 4 Y e a r o f i n t r o d u c t i o n Moore’s Law: • A new generation of memory chips is introduced every 3 years • Each new generation has 4 times as much memory as its predecessor • Computer technology doubles every 1.5 years: Example: DRAM capacity

19. Technology => dramatic change • Processor • logic capacity: about 30% per year • clock rate: about 20% per year • Memory • DRAM capacity: about 60% per year (4x every 3 years) • Memory speed: about 10% per year • Cost per bit: improves about 25% per year • Disk • capacity: about 60% per year Question: Does every thing look OK?

20. Software Evolution. • Machine language • Assembly language • High-level languages • Subroutine libraries • There is a large gap between what is convenient for computers & what is convenient for humans • Translation/Interpretation is needed between both

21. 0 0 0 0 0 0 0 0 1 0 1 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 1 1 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 1 1 1 0 0 0 0 1 1 0 0 0 0 0 1 0 0 0 0 1 1 0 0 0 1 1 0 0 0 1 1 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 1 1 0 0 1 1 1 1 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 1 0 1 0 1 1 0 0 1 1 1 1 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 1 0 1 1 0 0 0 1 1 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 Language Evolution swap (int v[], int k) { int temp temp = v[k]; v[k] = v[k+1]; v[k+1] = temp; } High-level language program (in C) swap: muli $2, $5, 4 add $2, $4, $2 lw $15, 0($2) lw $18, 4($2) sw $18, 0($2) sw $15, 4($2) jr $31 Assembly language program (for MIPS) Binary machine language program (for MIPS)

22. HW - SW Components • Hardware • Memory components • Registers • Register file • memory • Disks • Functional components • Adder, multiplier, dividers, . . . • Comparators • Control signals • Software • Data • Simple • Characters • Integers • Floating-point • Pointers • Structured • Arrays • Structures ( records) • Instructions • Data transfer • Arithmetic • Shift • Control flow • Comparison • . . .

23. Things You Will Learn • Assembly language introduction/Review • How to analyze program performance • How to design processor components • How to enhance processors performance (caches, pipelines, parallel processors, multiprocessors)

24. The Processor Chip

25. Branch Control Data cache Floating-point datapath Bus Integer data-path Instruction cache Processor Chip Major Blocks • Example: Intel Pentium • Area: 91 mm2 • ~ 3.3 million transistors ( 1 million for cache memory)

26. Memory • Categories • Volatile memory • Loses information when power is switched-off • Non-volatile memory • Keeps information when power is switched-off • Types • Cache: • Volatile • Fast but expensive • Smaller capacity • Placed closer to the processor • Main memory • Volatile • Less expensive • More capacity • Secondary memory • Nonvolatile • Low cost • Very slow • Unlimited capacity

27. Input-Output (I/O) • I/O devices have the hardest organization • Wide range of speeds • Graphics vs. keyboard • Wide range of requirements • Speed • Standard • Cost . . . • Least amount of research done in this area

28. Our Primary Focus • The processor (datapath and control) • Implemented using millions of transistors • Impossible to understand by looking at each transistor • We need abstraction • Hides lower-level details to offer simple model at higher level • Advantages • Intensive & thorough research into the depths • Reveals more information • Omits unneeded details • Helps us cope with complexity • Examples of abstraction: • Language hierarchy • Instruction set architecture (ISA)

29. Instruction Set Architecture (ISA) • Instruction set: • Complete set of instructions used by a machine • ISA: • Abstract interface between the HW and lowest-level SW. It encompasses information needed to write machine-language programs including • Instructions • Memory size • Registers used • . . .

30. Instruction Set Architecture (ISA) • ISA is considered part of the SW • Several implementations for the same ISA can exist • Modern ISA’s: • 80x86/Pentium/K6, PowerPC, DEC Alpha, MIPS, SPARC, HP • We are going to study MIPS • Advantages: • Different implementations of the same architecture • Easier to change than HW • Standardizes instructions, machine language bit patterns, etc. • Disadvantage: • Sometimes prevents using new innovations

31. Instruction Set Architecture (ISA) Fetch Instruction From Memory DecodeInstruction determine its size & action Fetch Operand data Execute instruction & compute results or status Store Result in memory Determine Next Instruction’s address • Instruction Execution Cycle

32. What Should we Learn? • A specific ISA (MIPS) • Performance issues - vocabulary and motivation • Instruction-Level Parallelism • How to Use Pipelining to improve performance • Exploiting Instruction-Level Parallelism w/ Software Approach • Memory: caches and virtual memory • I/O

33. What is Expected From You? • Read textbook & readings! • Be up-to-date! • Come back with your input & questions for discussion! • Appreciate and participate in teamwork!